ICS840004I-01 Datasheet | Integrated Circuit Systems

PRELIMINARY Integrated Circuit Systems, Inc. FEMTOCLOCKS™CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER Features - Four LVCMOS/LVTTL outputs, 15Ω typical output impedance - Selectable crystal oscillator interface or LVCMOS single-ended input - Supports the following output frequencies: 156.25MHz, 125MHz and 62.5MHz - RMS phase jitter @ 156.25MHZ (1.875MHz - 20MHz): 0.52ps (typical) - Output supply modes: Core/Output 3.3V/3.3V 3.3V/2.5V 2.5V/2.5V - -40°C to 85°C ambient operating temperature GENERAL DESCRIPTION The ICS840004I-01 is a 4 output LVCMOS/LVTTL Synthesizer optimized to generate Ethernet Hi Per Clock S™ reference clock frequencies and is a member of the Hi Per Clocks TM family of high performance clock solutions from ICS. Using a 25MHz, 18p F parallel resonant crystal, the following frequencies can be generated based on the 2 frequency select pins (F_SEL1:0): 156.25MHz, 125MHz, and 62.5MHz. The ICS840004I-01 uses ICS’ 3rd generation low phase noise VCO technology and can .. achieve 1ps or lower typical random rms phase jitter, easily meeting Ethernet jitter requirements. The ICS840004I-01 is packaged in a small 20-pin TSSOP package. FREQUENCY SELECT FUNCTION TABLE Inputs M Divider N Divider F_SEL1 F_SEL0 Value Value 0 0 25 4 0 1 1 1 0 1 25 25 25 5 10 5 M/N Ratio Value 6.25 5 2.5 5 Output Frequency (MHz) (25MHz Ref.) 156.25 125 62.5 125 BLOCK DIAGRAM OE Pullup F_SEL1:0 Pullup:Pullup n PLL_SEL Pulldown n XTAL_SEL XTAL_IN Pulldown 25MHz PIN ASSIGNMENT F_SEL0 nc n XTAL_SEL TEST_CLK OE MR n PLL_SEL VDDA nc VDD 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 F_SEL1 GND Q0 Q1 VDDO Q2 Q3 GND XTAL_IN XTAL_OUT XTAL_OUT TEST_CLK Pulldown F_SEL1:0 1 Phase Detector 00 01 10 11 Q0 N ÷4 ÷5 ÷10 ÷5 Q1 20-Lead TSSOP 6.5mm x 4.4mm x 0.92mm package body Q2 M = ÷25...